Benzodiazepines: Metabolism and Excretion

• Several benzo’s (diazepam, chlordiazepoxide, chlorazepate, halazepam, prazepam, chlorazepate) are first biotransformed to pharmacologically active intermediates

  • These intermediates are then degraded and excreted

• Thus, long-lasting benzo’s are so b/c they are first degraded to active intermediates, and both the parent drug and the intermediate are long-lasting/acting

  • Short-lasting benzo’s are not converted to active intermediates; they are metabolized directly into inactive products

• The elderly have a reduced ability to metabolize long-acting benzo’s (and their active metabolites)

  • Pharmacokinetics are not so drastically altered with the short-acting benzo’s (i.e., midazolam)

Category: Pharmacology Notes